Drive arrangement for the motorized adjustment of an adjustment element of a motor vehicle

ABSTRACT

The invention relates to a drive arrangement for the motorized adjustment of an adjustment element of a vehicle, wherein at least one drive comprising an electric drive motor and a drive control means and is connected to a supply, wherein the drive is designed in a non-self-locking manner, the drive motor operates as a generator and generates a generator voltage, wherein the drive control means has a driver unit for supplying electrical power to the at least one drive. The invention proposes that the drive control means has a switching device and has a detection device for detecting a non-motorized adjustment of the adjustment element, and that the drive control means, when a predetermined, non-motorized adjustment of the adjustment element is detected, connects the supply voltage to the supply connections of the driver unit by means of the switching device in one switching operation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.14/343,008, filed Nov. 17, 2014, which is a U.S. National StageApplication under 35 U.S.C. 371 of International Patent ApplicationSerial No. PCT/EP2012/003579, filed Aug. 24, 2012, which claims priorityfrom German Patent Application No. DE 10 2011 112 273.0, filed Sep. 5,2011, the disclosures of which are hereby incorporated by referenceherein in their entirety.

FIELD OF THE INVENTION

The invention relates to a drive arrangement for the motorizedadjustment of an adjustment element of a motor vehicle, and also to anadjustment element arrangement of a motor vehicle.

BACKGROUND

In the present case, the term “adjustment element” is to be understoodto be all-encompassing. Said term covers tailgates, trunk lids, enginehoods, doors, in particular side doors, luggage compartment floors orthe like, of a motor vehicle.

However, the drive arrangement under discussion is primarily used intailgates and side doors in motor vehicles. It is used for the motorizedadjustment of the respective adjustment element in the closing directionand in the opening direction. It is generally important in this casethat the drive arrangement also permits manual adjustment operation, inaddition to motorized adjustment operation. Manual adjustment operationis important particularly in the event of an emergency, for example inthe event of a crash or in the event of a power failure.

A known drive arrangement (DE 20 2005 007 155 U1) is associated with atailgate. The drive arrangement is equipped with two spindle driveswhich, in each case in a compact structural unit, have a drive motor, anintermediate gear mechanism with a clutch, and a spindle/spindle nutmechanism. A spring arrangement which counteracts the weight force ofthe associated tailgate is provided in the respective structural unit.The drive arrangement further has a drive control means which is used toactuate the two drives, in particular the two drive motors. The drivesare equipped in a non-self-locking manner, and therefore manualoperation can be realized in a simple manner.

The described drive arrangement can be used for the motorized adjustmentof tailgates of considerable size and/or substantial weight. Thiscreates new degrees of freedom when designing tailgates of this kind.However, the increase in weight is, in principle, also associated withan increased risk in the event of a failure of the drive components. Forexample, in the event of a fracture in the above spring arrangement, itis necessary to ensure that the tailgate does not drop in the closingdirection in an unbraked manner due to gravity.

In the case of the known drive arrangement (WO 2010/083999 A1) on whichthe invention is based, an overvoltage protection means of the drivecontrol means is used for the purpose of braking the drive in the eventof a non-motorized adjustment of the adjustment element above theadjustment speed for normal operation in the short-circuit mode. In thiscase, the drive control means is equipped with a driver unit forsupplying electrical drive power to the drive, said driver unit having aconventional H-bridge circuit.

In the case of the known drive arrangement, use is made of the fact thatthe drive motor operates as a generator in the event of a non-motorizedadjustment and generates a generator voltage by means of which theovervoltage protection means of the drive control means can betriggered. Triggering of the overvoltage protection means leads in thiscase to short-circuiting of the respective drive motor, this leading tocorresponding braking of the drive motor.

In the known drive arrangement, it is advantageous that rapid and heavybraking of the drive in the event of an emergency using simple means,and therefore a high level of operational reliability, are ensured.However, in the case of some applications, moderate braking would bedesirable, and this would be perceived by the user as an increase incomfort.

The invention is based on the problem of designing and developing theknown drive arrangement in such a way that the comfort of use isincreased while the operational reliability is maintained.

SUMMARY

The fundamental insight that moderate braking of the respective drivemotor can be implemented by the drive motor operating on the supply as agenerator for braking purposes, and not being merely short-circuited, isimportant. In this case, the supply is generally the vehicle battery.

Specifically, the drive control means has a switching device forconnecting the supply voltage to the driver unit and has a detectiondevice for detecting a non-motorized adjustment of the adjustmentelement, wherein the drive control means, when a predetermined,non-motorized adjustment of the adjustment element is detected, connectsthe supply voltage to the supply connections of the driver unit by meansof the switching device in one switching operation, so that the drivemotor, as discussed above, operates on the supply as a generator and isaccordingly braked.

By virtue of the proposed solution, the supply is fed to a certainextent by the drive motor which operates as a generator, this leading tothe braking effect on the drive motor generally being lower than in thecase of pure short-circuiting of the drive motor.

Furthermore, the probability of a generator voltage being produced at alevel which triggers an overvoltage protection means of the drivecontrol means is low, and this in turn could, as explained furtherabove, lead to short-circuiting of the drive motor.

In an embodiment, the polarity-reversal protection means of the drivecontrol means, in particular the switching device which is associatedwith the polarity-reversal protection means, is used to connect thesupply voltage to the driver unit in the event of the predetermined,non-motorized adjustment, in order to effect the above brakingoperation. This dual use of the polarity-reversal protection means whichis present in any case leads to a particularly simple realization.

In an embodiment, an overvoltage protection means is provided inaddition to the polarity-reversal protection means, the said overvoltageprotection means being triggered in the event of a limit generatorvoltage being exceeded and braking the drive motor in the short-circuitmode. In the event of extremely rapid, non-motorized operation, this maybe advantageous primarily when the above connection of the supplyvoltage is associated with a certain response time. In a case such asthis, it may be advantageous for the overvoltage protection means tobriefly respond with a corresponding short-circuit braking operation,until the supply voltage is connected by means of the switching deviceas discussed above. As a result, the operational reliability can beincreased in the case of an extremely rapid, non-motorized adjustment ofthe adjustment element.

According to a further teaching, the above problem is solved in the caseof an adjustment element arrangement.

The proposed adjustment element arrangement is equipped with anadjustment element, in particular a tailgate, of a motor vehicle andwith a proposed drive arrangement for the motorized adjustment of theadjustment element. Reference may be made to all embodiments whichrelate to the drive arrangement for explanation of this furtherteaching.

In an embodiment, the invention provides a drive arrangement for themotorized adjustment of an adjustment element of a motor vehicle,wherein at least one drive comprising an electric drive motor, such asDC motor, and a control means which is associated with the drive and isconnected to a supply, such as a vehicle battery, having a supplyvoltage are provided, wherein the drive is designed in anon-self-locking manner, so that, in the event of a non-motorizedadjustment of the adjustment element, the drive motor operates as agenerator and generates a generator voltage, wherein the drive controlmeans has a driver unit for supplying electrical power to the at leastone drive, wherein the drive control means has a switching device forconnecting the supply voltage to the driver unit and has a detectiondevice for detecting a non-motorized adjustment of the adjustmentelement, and in that the drive control means, when a predetermined,non-motorized adjustment of the adjustment element is detected, connectsthe supply voltage to the supply connections of the driver unit by meansof the switching device in one switching operation, so that the drivemotor operates on the supply as a generator and is accordingly braked.

In an embodiment, the generator voltage of the drive motor acts on thesupply connections of the driver unit by means of the driver unit, sothat the drive motor operates on the supply as a generator and isaccordingly braked when supply voltage is connected.

In an embodiment, the drive control means disconnects the supply voltagefrom the driver unit by means of the switching device in the stationarymode in any case.

In an embodiment, the drive control means has a control unit foractuating the driver unit.

In an embodiment, the drive control means, such as the control unit, canbe moved to an operating mode, in which the closure element can beadjusted by motor, and to a power-saving standby mode, in that thesupply voltage is connected to the supply connections of the driver unitby means of the switching device in the operating mode and isdisconnected from the driver unit in the standby mode.

In an embodiment, the drive control means has a polarity-reversalprotection means in respect of the polarity of the supply voltage, inthat the switching device is a constituent part of the polarity-reversalprotection means, and in that the switching device disconnects thesupply voltage from the driver unit, or allows said supply voltage to bedisconnected from said driver unit, when the polarity of the supplyvoltage is incorrect.

In an embodiment, the control unit is a constituent part of thepolarity-reversal protection means and disconnects the supply voltagefrom the driver unit, or allows said supply voltage to be disconnectedfrom said driver unit, by means of the switching device when thepolarity of the supply voltage is incorrect.

In an embodiment, the switching device always disconnects the supplyvoltage from the driver unit when there is no actuation by the controlunit, such as the control unit does not actuate the switching devicewhen the polarity of the supply voltage is incorrect, such as theswitching device is mechanically prestressed into a disconnectingswitching position.

In an embodiment, the adjustment speed of a non-motorized adjustment ofthe closure element can be ascertained by means of the detection device,and in that the drive control means connects the supply voltage to thesupply connections of the driver unit only when a switching adjustmentspeed is exceeded.

In an embodiment, the drive control means is equipped with anovervoltage protection means which can be triggered by a limit supplyvoltage being exceeded, and in that the arrangement is further made suchthat the overvoltage protection means can also be triggered by anon-motorized adjustment of the adjustment element when a limitgenerator voltage is exceeded, such as the overvoltage protection meanselectrically couples, such as short-circuits, the connections of thedrive motor to one another in the triggered state, and therefore brakesthe drive motor.

In an embodiment, the arrangement is made such that the overvoltageprotection means can only be triggered by a non-motorized adjustment ofthe adjustment element if, when the supply voltage is disconnected, theadjustment speed lies above a limit adjustment speed which is greaterthan the switching adjustment speed.

In an embodiment, the driver unit has an H-bridge circuit comprising twolow-side switches and two high-side switches for actuating the drivemotor, such as the H-bridge circuit has two half-bridges which each haveone of the low-side switches and one of the high-side switches, such asthe low-side switches and the high-side switches are designed asMOSFETs, and in that the arrangement is made such that the generatorvoltage acts at least partially on the supply connections of theH-bridge circuit by means of the body diodes of a high-side switch ofone half bridge and of a low-side switch of the other half bridge of theH-bridge circuit.

In an embodiment, two drives are provided, in that the drive controlmeans has a driver unit, such as an H-bridge circuit, for actuating thedrive motors of the drives in each case, and in that the respectivelycorresponding supply connections of the driver units, such as theH-bridge circuits, are connected, and in that the supply voltage can beconnected to the supply connections of the two driver units, such as thetwo H-bridge circuits, by means of the switching device.

In an embodiment, the adjustment element is designed as a tailgate, as atrunk lid, as an engine hood, as a door, such as side door, or as aluggage compartment floor of the motor vehicle.

In an embodiment, an adjustment element arrangement of a motor vehiclecomprising an adjustment element, such as a tailgate, and comprising adrive arrangement for the motorized adjustment of the adjustment elementdescribed herein is provided.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be explained in greater detail below with referenceto a drawing which illustrates only one exemplary embodiment. In thedrawing:

FIG. 1 shows a side view of the rear of a motor vehicle comprising atailgate and a proposed drive arrangement for the motorized adjustmentof the tailgate,

FIG. 2 shows a sectional illustration through one of the two drives ofthe drive arrangement according to FIG. 1,

FIG. 3 shows an entirely schematic illustration of the control unit andof the driver unit of the drive control means for the drive according toFIG. 2, and

FIG. 4 shows a block diagram of a half-bridge module of the H-bridgecircuit according to FIG. 3.

DETAILED DESCRIPTION

The drive arrangement which is illustrated in FIG. 1 is used for themotorized adjustment of a tailgate 1 of a motor vehicle. However, allother adjustment elements which are discussed in the introductory partof the description can also be advantageously used. All of the followingembodiments relating to a tailgate correspondingly equally apply for allof the other adjustment elements discussed in the introductory part.

The drive arrangement which is illustrated in FIG. 1 has two associatedidentical drives 2 which each have a drive motor 3. The drives 2 arearranged in the two side regions of a tailgate opening 4. Only one ofthe two drives 2 is illustrated in FIG. 1. FIG. 2 shows a side view ofthis drive 2. The following embodiments relate only to the drive 2 whichcan be seen in FIG. 1. However, they equally apply for any furtherdrives which may be present.

The drive 2 can include a DC motor. However, it is also feasible for anAC motor to be used here.

The drive arrangement is further equipped with a drive control means 5which is associated with the drive 2 and is connected in a conventionalmanner to a supply V with a supply voltage U_(V). In this case, “supply”very generally means the device which supplies the supply voltage U_(V)to the on-board electrical system. In this case, the said supply isgenerally a vehicle battery which is only schematically illustrated inFIG. 3. However, it is also feasible for the supply V to have circuitcomponents for voltage stabilization and/or for voltage smoothing. Thesupply voltage U_(V) is produced by the potential difference betweensupply potential V₀ and earth potential V_(Gnd).

In an embodiment, the drive control means 5 is associated with the twodrives 2. However, it is also feasible for each drive 2 to have its ownassociated drive control means 5.

The proposed drive arrangement allows for manual adjustment of thetailgate 1 without a relatively great deal structural expenditure sincethe drive 2 is designed in a non-self-locking manner. This means that,in the event of non-motorized, in particular manual, adjustment of thetailgate 1 by virtue of spring force or gravity, the drive motor 3operates as a generator. In the process, the drive motor 3 generates acorresponding generator voltage U_(G).

The drive control means 5 has a driver unit 6 for supplying electricaldrive power to the drive 2. Various options for designing the driverunit 6 are known from the prior art. In this case, an option involvesequipping the driver unit 6 with an H-bridge circuit which is still tobe explained.

FIG. 3 shows that the drive control means 5 has a switching device 7 forconnecting the supply voltage U_(V) to the supply connections 9, 10 ofthe driver unit 6. This switching device 7 can be a constituent part ofa polarity-reversal protection means VS, as will be explained.

In the present case, the term “connection of the supply voltage” is tobe understood broadly and comprises both the connection of the supplypotential V₀ and also the connection of the earth potential V_(Gnd) tothe supply connections 9, 10 of the driver unit 6. In the illustratedembodiment, only the supply potential V₀ is connected, as can begathered from the illustration according to FIG. 3.

The drive control means 5 is further equipped with a detection device 8for detecting a non-motorized adjustment of the tailgate 1. Numerousoptions are known for the purpose of realizing the detection device 8.The drive 2, in this case the spindle drive 2, can be equipped with anincremental sensor which, can be designed as a Hall sensor. All othertypes of sensors can be used in this case.

The detection device 8 can also be associated with the tailgate 1, sothat the tailgate adjustment is detected directly, and not indirectly bymeans of an adjustment of the drive 2.

There is always non-motorized adjustment of the tailgate for the drivecontrol means 5 when an adjustment of the tailgate 1 has been detectedby the detection device 8 without the driver unit 6 having beingactuated.

In this case, it is important that the drive control means 5, when apredetermined, non-motorized adjustment of the tailgate 1 is detected,connects the supply voltage U_(V) to the supply connections 9, 10 of thedriver unit 6 by means of the switching device 7 in one switchingoperation, so that the drive motor 3 operates on the supply V as agenerator, and is accordingly braked.

In the present case, the term “predetermined motorized adjustment of theadjustment element” means that each detection of a non-motorizedadjustment of the adjustment element 1 does not necessarily lead to aproposed switching operation. Rather, the switching process can beperformed only when a switching adjustment speed is exceeded. This isexplained in detail further below

One point of interest in the proposed solution is the fact that, in theevent of the predetermined, non-motorized adjustment of the adjustmentelement 1, a charging current is conducted from the drive motor 3, whichoperates as a generator, to the load V to a certain extent. At a supplyvoltage U_(V) which is different from zero, this charging current isalways less than the short-circuit current which is established whenmotor connections 11, 12 are short-circuited, and therefore theresulting braking action is less than the braking action which is causedby a short-circuit braking operation.

In the case of the illustrated embodiment, the generator voltage U_(G)of the drive motor 3 acts on the supply connections 9, 10 of the driverunit 6 by means of the driver unit 6, so that the drive motor 3 operateson the supply V as a generator and is accordingly braked when, asexplained above, supply voltage U_(v) is connected. Closing theswitching device 7 which is illustrated in FIG. 3 is sufficient forconnecting the supply voltage U_(V) to the supply connections 9, 10.

The way in which the generator voltage U_(G) of the drive motor 3 actsspecifically on the supply connections 9, 10 of the driver unit 6 bymeans of the driver unit 6 will be explained in greater detail furtherbelow with reference to a driver unit 6 comprising an H-bridge circuit.

In particular in order to reduce losses in a stationary mode as far aspossible, provision can be made for the drive control means 5 todisconnect the supply voltage U_(V) from the driver unit 6 by means ofthe switching device 7 in the stationary mode in any case. In this case,the supply voltage U_(V) is connected to the driver unit 6 whenmotorized adjustment is intended to take place or when an above,predetermined, non-motorized adjustment of the adjustment element 1 hasbeen detected.

The drive control means 5 can be equipped with a control unit 13 inorder to actuate the driver unit 6. The control unit 13 can also takeson the function of a regulation means which converts the predeterminedadjustment movement profiles. Furthermore, the control unit 13 alsotakes on the actuation of the switching unit 7 in this case.Accordingly, the control unit 13 is coupled to the driver unit 6 bymeans of the control lines 13 a, 13 b, to the switching device 7 bymeans of the control line 13 c, and to the detection device 8 by meansof the control line 13 d.

The control unit 13 is generally a microcontroller which is positionedin a decentralized manner in the region of the drive arrangement.However, it is also feasible for the control unit 13 to be a constituentpart of a central motor vehicle control means.

The drive control means 5, such as the control unit 13, can be moved,for the purpose of power-saving operation, not only to an operating modein which the tailgate 1 can be adjusted by motor, but also to apower-saving standby mode. Only those sections of the control unit 13which are required for later waking up the control unit 13, that is tosay for moving the control unit 13 to the operating mode, are generallyactivated in the standby mode. The control unit 13 can be woken up byuser operation by means of an operating device 14 which is coupled tothe control unit 13 by means of a control line 13 e. An operating device14 of this kind can be a pushbutton which is arranged on the tailgate 1,or the like.

The supply voltage U_(V) can be connected to the supply connections 9,10 of the driver unit 6 by means of the switching device 7 in theoperating mode, and is disconnected from the driver unit 6 in thestandby mode. This is also particularly advantageous in respect ofrealizing a polarity-reversal protection means VS. In a particularlyrefinement, the drive control means 5 is equipped specifically with apolarity-reversal protection means VS in respect of the correct polarityof the supply voltage U_(V), wherein the switching device 7 can be aconstituent part of the polarity-reversal protection means VS. Thefunction of the polarity-reversal protection means VS is to disconnectthe supply voltage U_(V) from the driver unit 6, or allow said supplyvoltage to be disconnected from said driver unit, when the polarity ofthe supply voltage U_(V) is incorrect.

In an embodiment, the control unit 13 is a constituent part of thepolarity-reversal protection means VS, wherein the control unit 13disconnects the supply voltage U_(V) from the driver unit 6, or allowssaid supply voltage to be disconnected from said driver unit, by meansof the switching device 7 when the polarity of the supply voltage U_(V)is incorrect.

Specifically, the arrangement is made such that the switching device 7always disconnects the supply voltage U_(V) from the driver unit 6 whenthere is no actuation by the control unit 13, and the control unit 13does not actuate the switching device 7 when the polarity of the supplyvoltage U_(V) is incorrect. In a refinement, the switching device 7 ismechanically prestressed into a disconnecting switching position in thiscase. This is the case when the switching device 7 is designed as anelectromechanical relay.

It has already been noted that the proposed connection of the supplyvoltage U_(V) to the supply connections 9, 10 of the driver unit 6 isintended to take place only in the event of a predetermined,non-motorized adjustment of the tailgate 1. In an embodiment, theadjustment speed of a non-motorized adjustment of the tailgate 1 can beascertained by means of the detection device 8, and the drive controlmeans 5 connects the supply voltage U_(V) to the driver unit 6 only whena switching adjustment speed is exceeded. This ensures that slow andtherefore non-hazardous, non-motorized adjustment movements of thetailgate 1, such as manual adjustment movements in line with normaloperation, can be performed in an unbraked manner. Braking is performedonly after a predetermined switching adjustment speed, which occurs inthe event of an emergency for example, is exceeded.

In an embodiment, the drive control means 5 is also equipped with anovervoltage protection means US which is discussed in the introductorypart of the description and can be triggered by a limit supply voltageU_(V) being exceeded. In this case, the arrangement is further made suchthat the overvoltage protection means US can also be triggered by anon-motorized adjustment of the tailgate 1 when a limit generatorvoltage U_(G) is exceeded. In a refinement, the overvoltage protectionmeans US electrically couples the motor connections 11, 12 of the drivemotor 3 to one another in the triggered state, as a result of which thedrive motor 3 is again braked. In an embodiment, triggering of theovervoltage protection means US leads to short-circuiting of the motorconnections 11, 12.

Therefore, overall, two mechanisms for braking the drive motor 3 in theevent of non-motorized adjustment of the tailgate 1 are provided. Inthis case, the arrangement can be made such that the overvoltageprotection means US can only be triggered by a non-motorized adjustmentof the tailgate 1 if, when the supply voltage U_(V) is disconnected fromthe driver unit 6, the adjustment speed lies above a limit adjustmentspeed which is, in turn, greater than the switching adjustment speed.This means that the drive motor 3 is braked fundamentally by theswitching device 7 in the event of non-motorized adjustment of thetailgate 1. One exception is in the case of an extremely rapidnon-motorized adjustment of the tailgate 1 when the supply voltage U_(V)is still disconnected, this leading to triggering of the overvoltageprotection means US. Therefore, the overvoltage protection means USprovides additional security in the case of extreme non-motorizedadjustment movements of the tailgate 1.

The manner of operation of an above overvoltage protection means US andits use for braking the tailgate 1 is the subject matter of patentapplication WO 2010/083999 A1 which was published by the same applicantand of which the content, in its entirety, is included in the subjectmatter of the present application.

As shown in FIGS. 3 and 4, the drive control means 5 is equipped with anH-bridge circuit 15 comprising two low-side switches 16, 17 and twohigh-side switches 18, 19 for actuating the drive motor 3. The H-bridgecircuit 15 is usually constructed with two half-bridges 15 a, 15 b whicheach have one of the low-side switches 16, 17 and one of the high-sideswitches 18, 19. The low-side switches 16, 17 and the high-side switches18, 19 are connected in series in respect of their switching outputs.The motor connections 11, 12 of the drive motor 3 are connected to thecontact points of the pairs of switches 16, 18; 17, 90 which areconnected in series in each case.

In an embodiment, the overvoltage protection means US connects the twohigh-side switches 18, 19 and blocks the two low-side switches 16, 17 inthe triggered state. However, it is also feasible, conversely, for thetwo low-side switches 16 and 17 to be connected and the two high-sideswitches 18, 19 to be blocked in the triggered state of the overvoltageprotection means US. In the two above-mentioned cases, the drive motor 3is short-circuited and is in the braking mode.

A series of advantageous variants for realizing the low-side switches16, 17 and the high-side switches 18, 19 are feasible. In an embodiment,said switches 16, 17, 18, 19 are designed as MOSFETs, wherein thelow-side switches 16, 17 are N-channel MOSFETs and the high-sideswitches 18, 19 are P-channel MOSFETs. The gate connections 16 a, 17 a,18 a, 19 a of the switches 16, 17, 18, 19 are coupled to a logic unit 20which is illustrated only in FIG. 4 which is still to be explained.

The arrangement is now made such that the generator voltage is at leastpartially connected to the supply connections 9, 10 of the driver unit6, in this case the H-bridge circuit 15, by means of the body diodes 21of a high-side switch 18, 19 of one half bridge 15 a, 15 b and of alow-side switch 16, 17 of the other half bridge 15 a, 15 b of theH-bridge circuit.

The existence of the body diodes 21 is inherent in MOSFET switchingelements. For illustration purposes, the body diodes 21 are illustratedas discrete components in FIG. 4 which is still to be explained. Whenthe supply voltage U_(V) is connected to the supply connections 9, 10 ofthe driver unit 6 by means of the switching device 7, the chargingcurrent of the drive motor 3, which is operated as a generator, flowsacross the body diodes 21 and across the switching device 7 to the loadV, this causing the described braking of the drive motor 3, in the eventof non-motorized adjustment of the tailgate 1. FIG. 3 shows that thegenerator voltage U_(G) is partially connected to the supply voltageU_(V) in any case, it being possible for this to lead briefly to afluctuation in the supply voltage U_(V) in any case. However, thefluctuation in the supply voltage U_(V) moves within acceptable limitsowing to the rapid charging compensation between the drive motor 3,which operates as a generator, and the supply V.

The proposed drive control means 5 comprising standard components can berealized in a cost-effective manner by the two half bridges 15 a, 15 bof the H-bridge circuit 15 each being designed as integral part-bridgemodules, and by the two half-bridge modules each being equipped with aseparate overvoltage protection means US. In this case, “integrated”means that the half-bridge modules are integrated circuits. FIG. 4 showsthe basic construction of a half-bridge module of this kind.

The half-bridge module which is illustrated in FIG. 4 is equipped with alogic unit 20 for actuating the low-side switch 16 and the high-sideswitch 18. In this case, the overvoltage protection means US of the twohalf-bridge modules in each case has a detection unit 22, which isconnected to the logic unit 20, for detecting whether the supply voltageU_(V) has exceeded the limit supply voltage.

It has already been noted that the drive arrangement can have two drives2, wherein the drive control means 5 for actuating the drive motors 3 ofthe drives 2 in each case has a driver unit 6, in an embodiment aH-bridge circuit 15 in each case, wherein the respectively correspondingsupply connections 9, 10 of the driver units 6, in an embodiment theH-bridge circuits 15, are connected to one another, and wherein thesupply voltage U_(V) can be connected to the supply connections 9, 10 ofthe two driver units 6, in an embodiment the two H-bridge circuits 15,by means of the switching device 7.

The proposed solution can be used for all possible adjustment elements 1of a motor vehicle. The adjustment element 1 can include a tailgate, atrunk lid, an engine hood, a door, in particular side door, or a luggagecompartment floor, of a motor vehicle.

According to a further teaching, which is likewise granted independentsignificance, an adjustment element arrangement of a motor vehiclecomprising an adjustment element 1, in particular a tailgate 1, andcomprising an above-described, proposed drive arrangement with themotorized adjustment of the adjustment element 1 is claimed. Referencemay be made to the above statements in their entirety in respect of theproposed drive arrangement.

The invention claimed is:
 1. A drive arrangement for the motorized adjustment of an adjustment element of a motor vehicle, wherein at least one drive comprising an electric drive motor and a control means which is associated with the drive and is connected to a supply having a supply voltage are provided, wherein the drive is designed in a non-self-locking manner, so that, in the event of a non-motorized adjustment of the adjustment element, the drive motor operates as a generator and generates a generator voltage, wherein the drive control means has a driver unit for supplying electrical power to the at least one drive, wherein the drive control means has a switching device for connecting the supply voltage to the driver unit and has a detection device for detecting a non-motorized adjustment of the adjustment element, and in that the drive control means, when a predetermined, non-motorized adjustment of the adjustment element is detected, connects the supply voltage to the supply connections of the driver unit by means of the switching device in one switching operation, so that the drive motor operates on the supply as a generator and is accordingly braked.
 2. The drive arrangement according to claim 1, wherein the generator voltage of the drive motor acts on the supply connections of the driver unit by means of the driver unit, so that the drive motor operates on the supply as a generator and is accordingly braked when supply voltage is connected.
 3. The drive arrangement according to claim 1 wherein the drive control means disconnects the supply voltage from the driver unit by means of the switching device in the stationary mode in any case.
 4. The drive arrangement according to claim 1 wherein the drive control means has a control unit for actuating the driver unit.
 5. The drive arrangement according to claim 1 wherein the drive control means can be moved to an operating mode, in which the closure element can be adjusted by motor, and to a power-saving standby mode, in that the supply voltage is connected to the supply connections of the driver unit by means of the switching device in the operating mode and is disconnected from the driver unit in the standby mode.
 6. The drive arrangement according to claim 1 wherein the control unit is a constituent part of the polarity-reversal protection means and disconnects the supply voltage from the driver unit, or allows said supply voltage to be disconnected from said driver unit, by means of the switching device when the polarity of the supply voltage is incorrect.
 7. The drive arrangement according to claim 1 wherein the switching device always disconnects the supply voltage from the driver unit when there is no actuation by the control unit.
 8. The drive arrangement according to claim 7, wherein the switching device is mechanically prestressed into a disconnecting switching position.
 9. The drive arrangement according to claim 1 wherein the adjustment speed of a non-motorized adjustment of the closure element can be ascertained by means of the detection device, and in that the drive control means connects the supply voltage to the supply connections of the driver unit only when a switching adjustment speed is exceeded.
 10. The drive arrangement according to claim 1 wherein the drive control means is equipped with an overvoltage protection means which can be triggered by a limit supply voltage being exceeded, and in that the arrangement is further made such that the overvoltage protection means can also be triggered by a non-motorized adjustment of the adjustment element when a limit generator voltage is exceeded.
 11. The drive arrangement according to claim 10, wherein the arrangement is made such that the overvoltage protection means can only be triggered by a non-motorized adjustment of the adjustment element if, when the supply voltage is disconnected, the adjustment speed lies above a limit adjustment speed which is greater than the switching adjustment speed.
 12. The drive arrangement according to claim 10, wherein the overvoltage protection means electrically couples the connections of the drive motor to one another in the triggered state, and therefore brakes the drive motor.
 13. The drive arrangement according to claim 1 wherein the driver unit has an H-bridge circuit comprising two low-side switches and two high-side switches for actuating the drive motor and in that the arrangement is made such that the generator voltage acts at least partially on the supply connections of the H-bridge circuit by means of the body diodes of a high-side switch of one half bridge and of a low-side switch of the other half bridge of the H-bridge circuit.
 14. The drive arrangement according to claim 13, wherein the H-bridge circuit comprises two half-bridges, which each comprise one of the low-side switches and one of the high-side switches.
 15. The drive arrangement according to claim 1 wherein two drives are provided, in that the drive control means has a driver unit for actuating the drive motors of the drives in each case, and in that the respectively corresponding supply connections of the driver units are connected, and in that the supply voltage can be connected to the supply connections of the two driver units by means of the switching device.
 16. The drive arrangement according to claim 15, wherein the driver unit, comprises an H-bridge circuit.
 17. The drive arrangement according to claim 1 wherein the adjustment element is designed as a tailgate, as a trunk lid, as an engine hood, as a door or as a luggage compartment floor of the motor vehicle.
 18. An adjustment element arrangement of a motor vehicle comprising an adjustment element and comprising a drive arrangement for the motorized adjustment of the adjustment element according to claim
 1. 19. The drive arrangement according to claim 1, wherein the supply comprises a vehicle battery.
 20. The drive arrangement according to claim 1, wherein the drive control means has a polarity-reversal protection means in respect of the polarity of the supply voltage, in that the switching device is a constituent part of the polarity-reversal protection means, and in that the switching device disconnects the supply voltage from the driver unit, or allows said supply voltage to be disconnected from said driver unit, when the polarity of the supply voltage is incorrect. 